The invoice number is one of the most important components of an invoice. Every invoice should possess a unique invoice number. The WebToffee’s WooCommerce PDF Invoices, Packing Slips, and Credit Notes plugin helps to create unique invoice numbers for upcoming orders either using a custom number series or by using the order number as the invoice number. The plugin also allows resetting invoice numbers for upcoming orders.
Creating invoice numbers for upcoming orders
Custom invoice number series
- Navigate to Invoice/Packing > Invoice > General from your WordPress dashboard.
- Head on to the Invoice number section and find the Invoice number format option.
- Choose Custom number to create a custom invoice number series.
- As a next step, enter the desired starting number for invoices in the ‘Invoice starting number’ field.
- Add a prefix and suffix to your invoice number in the specified fields. You can leave the fields blank if you prefer not to add one. To add a date format as the suffix, click on the suffix field and choose a format from the dropdown menu.
- Indicate the total length of the invoice number, excluding the length of prefixes and suffixes in the ‘Invoice number length’ field. If the length of the generated invoice number is less than the provided, it will be padded with ‘0’.
- Finally, click on Update Settings to save the changes.
Order number as invoice number
- Navigate to Invoice/Packing > Invoice > General from your WordPress dashboard.
- Head on to the Invoice number section.
- In the Invoice number format option, choose Order number to use the order number as the invoice number.
- Add a prefix and suffix to your invoice number in the specified fields. You can leave the fields blank if you prefer not to add one.
- Enter the total length of invoice numbers, excluding the length of prefixes and suffixes in the ‘Invoice number length’ field. If the length of the generated invoice number is less than the provided, it will be padded with ‘0’.
- Finally, click on Update Settings to save the changes.
To learn more about resetting invoice numbers, check out the following article: Reset Existing Invoice Numbers.
Sjoerd Kleijheeg
September 11, 2025
Next to setting a custom invoice number, is it possible to do this for the order number as well? Since I installed this plugin it changed the basics of the order number. Where can I change that? I see an adjustable field in the invoice template, but nomatter the change I make to it, after refreshing, it does not hold the change. What can I do?
Hema
September 22, 2025
Hi there,
The plugin provides the option to display the custom invoice number (set in the plugin settings) or the default WooCommerce order ID as the invoice number. However, please note that the Invoice plugin does not offer the functionality to assign sequential number for WooCommerce order ID.
If you’d like to make WooCommerce order IDs sequential so that the order number and invoice number match, you can use our Sequential Order Number plugin to achieve this.
Regarding the issue you mentioned where your changes are not saving, kindly reach out to our technical support team and share a brief screen recording of the problem. This will help us better understand the situation and assist you further.
Kelvin Lee
October 31, 2023
I have a front end report for admin user, please advise how I can make a link to download the invoice.
Sanjai Valsan
November 2, 2023
Hi Kelvin Lee,
Thanks for reaching out!
Currently, the plugin doesn’t provide the functionality you have specified.
Kelvin Lee
October 31, 2023
I want to have the invoice format like INV20231011-1 but I can’t set it with
INV[Y data-val=’order_date’][m data-val=’order_date’][d data-val=’order_date’]-
I need to use the order date instead of current date.
Please advise how I can do.
Sanjai Valsan
November 2, 2023
Hi Kelvin Lee,
Thanks for reaching out!
To set the invoice format as INV20231011-1, follow these steps:
1. Select custom number series for setting the invoice number.
2. Set the “Invoice start number” to 1.
3. Select the invoice number format as [prefix][number].
4. Add
INV[Y][m][d]-as the prefix.